If you don't care as much about the inner geometry and precision of the wall thickness, and want something that runs reasonably quickly, you can do something like this old "shell_3d()" module I came up with: https://github.com/clothbot/makerbot/blob/master/fabjects/libraries/constructors/shell_3d.scad It's basically a union of shifted-difference operations. Handy if you want to be asymmetric in your thicknesses, e.g. thicker top relative to bottom and sides to allow for more 3d-printed internal self-supporting structure. Andrew. -- View this message in context: http://forum.openscad.org/make-an-object-hollow-with-constant-wall-thickness-tp14255p14270.html Sent from the OpenSCAD mailing list archive at Nabble.com.